Improvement in bit-braces



UNITED STATEs PATENT OEETGE.

CHARLESv H. AMIDON, OF BUFFALO, NEW YORK.

IMPROVEMENT IN'BlT-BRACES.

Specification forming part of Letters Patent No. 210,075, dated November 19, 1878,' application filed September 26, 1878.

To all whom 'it may concern:

Be it known that I, CHARLES H. Ammon, ot' the city of Buffalo, in the county ot' Erie and State of New York, have invented new and useful Improvements in Bit-Braces, of which the following is a specification, refer-g4 ence heilig had to the accompanying drawing.

This invention relates to that class of bitbraces in which the socket'is provided with a diametrical slot, which contains a pair of clamping-jaws, which are opened and closed by means of a sleeve-nut, for securiu g and releasing the bit.

My invention consists of the particular construction ofthe socket portion of the brace and concomitant parts, so as to cause the ybit to be iirmly secured in the socket and to be quickly centered, and at the same time enable tlle device t0 be cheaply manuilactured, as will be hereinafter fully set forth.

In the accompanying drawings, Figure l is a sectional elevation of the socket portion of 'a bit-brace containing myimprovements. Fig. 2 is an elevation thereof' with the sleeve-nut and clamps removed. Fig. 3 is an end View thereof. Fig. 4 is a horizontal section in line Fig. l. Fig. 5 is a side elevation of one ofthe clamps. Fig. 6 is a face view thereof.

Like letters ot' reference designate like parts, in each ofthe iigurcs.

A represents the end ot' the brace, of ordinary and well-known construction; and B, the socket portion thereof, provided with a rectangular socket, b, in which the bit is secured. cis a slot or lnortise extending dialnetrically through the socket portion l, and diagonally through the socket b thereof. "he slot c is arranged at a short distance from the end of the portion B, so as to leave at said end a ring or annular end portion, d, entire. cis a screw-thread formed on the lower enlarged part of the socketv portion B.

FF are two clamping-jaws arranged loosely in the slot c. These jaws are made tapering` toward their upper ends, where they are provided with a sharp transverse edge, j; adapted to firmly gripe the shank" of the bit. The lowe1 portions of the adjacent faces of the jaws F are constructed with Vshaped depressions g, for engaging against the square shank of the bit. The jaws F are so constructed that the lower portions of their backs will project slightly beyond the surface of the socket portion B, while the upper portions ot' theirbacksare curved inwardly and depressed below the surface ot' the portion B.

H is the sleeve by which the jaws F are opened and closed. It is provided at its lower end with an internal screw-thread, engaging with the thread c of the portion 1B. ll 1e ripper end Il. of the sleeve II is constructed slightly comf'erging or conical on its inner side, so that its conical end It upon the curved backs of the clamps F, and compresses the upper ends thereof, while by a reverse movement of the Sleeve the clalnps are released.

The annular portion d of the socket portion B, above the slot c, serves to guide the shank ofthe bit into the socket Z), and also holds the jaws Fin place without any special fastening device, and relieves the-jaws from strains in turning the bit.

In clamping the shank of a bi t, the edges j' of the jaws F impinge against two opposite edges of the shank, and iirml y secure thc same in thesocket.,

Aliathe parts. ot' my improved bit-brace are easily made and readily put together, thereby producing a very eiicient and serviceable brace at comparatively small expense.

I claim as my invention- In a bit-brace, the combination, with the socket portion B, provided with a diametrienl slot, c, having an annular end, d, ot' two clamping-jaws, F, provided with transverse edges f, adapted to seize the shank of the bit, V- shaped depressions g in the lower portions ot' their faces, and having the upper portions ot' their curved backs depressed below the surface of the portion l, and a screw-sleeve, Il, provided with a converging end, 7L, substantially as shown and described.

CHARLES l-I. AMIDON.

Witnesses:

JNO. J. BONNER, EDWARD J. BRADY,

the sleeve, as it is screwed down, bears with 

